/*
 * Copyright 2002-2010 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

using System.Collections;
using System.Collections.Specialized;
using Spring.Util;

namespace Spring.Collections;

/// <summary>
/// Synchronized <see cref="Hashtable"/> that, unlike hashtable created
/// using <see cref="Hashtable.Synchronized"/> method, synchronizes
/// reads from the underlying hashtable in addition to writes.
/// </summary>
/// <remarks>
/// <p>
/// In addition to synchronizing reads, this implementation also fixes
/// IEnumerator/ICollection issue described at
/// http://msdn.microsoft.com/en-us/netframework/aa570326.aspx
/// (search for SynchronizedHashtable for issue description), by implementing
/// <see cref="IEnumerator"/> interface explicitly, and returns thread safe enumerator
/// implementations as well.
/// </p>
/// <p>
/// This class should be used whenever a truly synchronized <see cref="Hashtable"/>
/// is needed.
/// </p>
/// </remarks>
/// <author>Aleksandar Seovic</author>
[Serializable]
public class SynchronizedHashtable : IDictionary, ICollection, IEnumerable, ICloneable
{
    private readonly bool _ignoreCase;
    private readonly Hashtable _table;

    /// <summary>
    /// Initializes a new instance of <see cref="SynchronizedHashtable"/>
    /// </summary>
    public SynchronizedHashtable()
        : this(new Hashtable(), false)
    {
    }

    /// <summary>
    /// Initializes a new instance of <see cref="SynchronizedHashtable"/>
    /// </summary>
    public SynchronizedHashtable(bool ignoreCase)
        : this(new Hashtable(), ignoreCase)
    {
    }

    /// <summary>
    /// Initializes a new instance of <see cref="SynchronizedHashtable"/>, copying initial entries from <param name="dictionary"/>
    /// handling keys depending on <param name="ignoreCase"/>.
    /// </summary>
    public SynchronizedHashtable(IDictionary dictionary, bool ignoreCase)
    {
        AssertUtils.ArgumentNotNull(dictionary, "dictionary");
        this._table = (ignoreCase) ? CollectionsUtil.CreateCaseInsensitiveHashtable(dictionary) : new Hashtable(dictionary);
        this._ignoreCase = ignoreCase;
    }

    /// <summary>
    /// Creates a <see cref="SynchronizedHashtable"/> instance that
    /// synchronizes access to the underlying <see cref="Hashtable"/>.
    /// </summary>
    /// <param name="other">the hashtable to be synchronized</param>
    protected SynchronizedHashtable(Hashtable other)
    {
        AssertUtils.ArgumentNotNull(other, "other");
        this._table = other;
    }

    /// <summary>
    /// Creates a <see cref="SynchronizedHashtable"/> wrapper that synchronizes
    /// access to the passed <see cref="Hashtable"/>.
    /// </summary>
    /// <param name="other">the hashtable to be synchronized</param>
    public static SynchronizedHashtable Wrap(Hashtable other)
    {
        return new SynchronizedHashtable(other);
    }

    ///<summary>
    ///Gets a value indicating whether the <see cref="T:System.Collections.IDictionary"></see> object is read-only.
    ///</summary>
    ///<returns>
    ///true if the <see cref="T:System.Collections.IDictionary"></see> object is read-only; otherwise, false.
    ///</returns>
    public bool IsReadOnly
    {
        get
        {
            lock (SyncRoot)
            {
                return _table.IsReadOnly;
            }
        }
    }

    ///<summary>
    ///Gets a value indicating whether the <see cref="T:System.Collections.IDictionary"></see> object has a fixed size.
    ///</summary>
    ///<returns>
    ///true if the <see cref="T:System.Collections.IDictionary"></see> object has a fixed size; otherwise, false.
    ///</returns>
    public bool IsFixedSize
    {
        get
        {
            lock (SyncRoot)
            {
                return _table.IsFixedSize;
            }
        }
    }

    ///<summary>
    ///Gets a value indicating whether access to the <see cref="T:System.Collections.ICollection"></see> is synchronized (thread safe).
    ///</summary>
    ///<returns>
    ///true if access to the <see cref="T:System.Collections.ICollection"></see> is synchronized (thread safe); otherwise, false.
    ///</returns>
    public bool IsSynchronized
    {
        get { return true; }
    }

    ///<summary>
    ///Gets an <see cref="T:System.Collections.ICollection"></see> object containing the keys of the <see cref="T:System.Collections.IDictionary"></see> object.
    ///</summary>
    ///<returns>
    ///An <see cref="T:System.Collections.ICollection"></see> object containing the keys of the <see cref="T:System.Collections.IDictionary"></see> object.
    ///</returns>
    public ICollection Keys
    {
        get
        {
            lock (SyncRoot)
            {
                return _table.Keys;
            }
        }
    }

    ///<summary>
    ///Gets an <see cref="T:System.Collections.ICollection"></see> object containing the values in the <see cref="T:System.Collections.IDictionary"></see> object.
    ///</summary>
    ///<returns>
    ///An <see cref="T:System.Collections.ICollection"></see> object containing the values in the <see cref="T:System.Collections.IDictionary"></see> object.
    ///</returns>
    public ICollection Values
    {
        get
        {
            lock (SyncRoot)
            {
                return _table.Values;
            }
        }
    }

    ///<summary>
    ///Gets an object that can be used to synchronize access to the <see cref="T:System.Collections.ICollection"></see>.
    ///</summary>
    ///<returns>
    ///An object that can be used to synchronize access to the <see cref="T:System.Collections.ICollection"></see>.
    ///</returns>
    public object SyncRoot
    {
        get { return _table.SyncRoot; }
    }

    ///<summary>
    ///Gets the number of elements contained in the <see cref="T:System.Collections.ICollection"></see>.
    ///</summary>
    ///<returns>
    ///The number of elements contained in the <see cref="T:System.Collections.ICollection"></see>.
    ///</returns>
    public int Count
    {
        get
        {
            lock (SyncRoot)
            {
                return _table.Count;
            }
        }
    }

    ///<summary>
    ///Adds an element with the provided key and value to the <see cref="T:System.Collections.IDictionary"></see> object.
    ///</summary>
    ///<param name="value">The <see cref="T:System.Object"></see> to use as the value of the element to add. </param>
    ///<param name="key">The <see cref="T:System.Object"></see> to use as the key of the element to add. </param>
    ///<exception cref="T:System.ArgumentException">An element with the same key already exists in the <see cref="T:System.Collections.IDictionary"></see> object. </exception>
    ///<exception cref="T:System.ArgumentNullException">key is null. </exception>
    ///<exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.IDictionary"></see> is read-only.-or- The <see cref="T:System.Collections.IDictionary"></see> has a fixed size. </exception><filterpriority>2</filterpriority>
    public void Add(object key, object value)
    {
        lock (SyncRoot)
        {
            _table.Add(key, value);
        }
    }

    ///<summary>
    ///Removes all elements from the <see cref="T:System.Collections.IDictionary"></see> object.
    ///</summary>
    ///<exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.IDictionary"></see> object is read-only. </exception><filterpriority>2</filterpriority>
    public void Clear()
    {
        lock (SyncRoot)
        {
            _table.Clear();
        }
    }

    ///<summary>
    ///Creates a new object that is a copy of the current instance.
    ///</summary>
    ///<returns>
    ///A new object that is a copy of this instance.
    ///</returns>
    public object Clone()
    {
        lock (SyncRoot)
        {
            return new SynchronizedHashtable(this, _ignoreCase);
        }
    }

    ///<summary>
    ///Determines whether the <see cref="T:System.Collections.IDictionary"></see> object contains an element with the specified key.
    ///</summary>
    ///<returns>
    ///true if the <see cref="T:System.Collections.IDictionary"></see> contains an element with the key; otherwise, false.
    ///</returns>
    ///<param name="key">The key to locate in the <see cref="T:System.Collections.IDictionary"></see> object.</param>
    ///<exception cref="T:System.ArgumentNullException">key is null. </exception><filterpriority>2</filterpriority>
    public bool Contains(object key)
    {
        lock (SyncRoot)
        {
            return _table.Contains(key);
        }
    }

    ///<summary>
    /// Returns, whether this <see cref="IDictionary"/> contains an entry with the specified <paramref name="key"/>.
    ///</summary>
    ///<param name="key">The key to look for</param>
    ///<returns><see lang="true"/>, if this <see cref="IDictionary"/> contains an entry with this <paramref name="key"/></returns>
    public bool ContainsKey(object key)
    {
        lock (SyncRoot)
        {
            return _table.ContainsKey(key);
        }
    }

    ///<summary>
    /// Returns, whether this <see cref="IDictionary"/> contains an entry with the specified <paramref name="value"/>.
    ///</summary>
    ///<param name="value">The value to look for</param>
    ///<returns><see lang="true"/>, if this <see cref="IDictionary"/> contains an entry with this <paramref name="value"/></returns>
    public bool ContainsValue(object value)
    {
        lock (SyncRoot)
        {
            return _table.ContainsValue(value);
        }
    }

    ///<summary>
    ///Copies the elements of the <see cref="T:System.Collections.ICollection"></see> to an <see cref="T:System.Array"></see>, starting at a particular <see cref="T:System.Array"></see> index.
    ///</summary>
    ///<param name="array">The one-dimensional <see cref="T:System.Array"></see> that is the destination of the elements copied from <see cref="T:System.Collections.ICollection"></see>. The <see cref="T:System.Array"></see> must have zero-based indexing. </param>
    ///<param name="index">The zero-based index in array at which copying begins. </param>
    ///<exception cref="T:System.ArgumentNullException">array is null. </exception>
    ///<exception cref="T:System.ArgumentException">The type of the source <see cref="T:System.Collections.ICollection"></see> cannot be cast automatically to the type of the destination array. </exception>
    ///<exception cref="T:System.ArgumentOutOfRangeException">index is less than zero. </exception>
    ///<exception cref="T:System.ArgumentException">array is multidimensional.-or- index is equal to or greater than the length of array.-or- The number of elements in the source <see cref="T:System.Collections.ICollection"></see> is greater than the available space from index to the end of the destination array. </exception><filterpriority>2</filterpriority>
    public void CopyTo(Array array, int index)
    {
        lock (SyncRoot)
        {
            _table.CopyTo(array, index);
        }
    }

    ///<summary>
    ///Returns an <see cref="T:System.Collections.IDictionaryEnumerator"></see> object for the <see cref="T:System.Collections.IDictionary"></see> object.
    ///</summary>
    ///<returns>
    ///An <see cref="T:System.Collections.IDictionaryEnumerator"></see> object for the <see cref="T:System.Collections.IDictionary"></see> object.
    ///</returns>
    public IDictionaryEnumerator GetEnumerator()
    {
        lock (SyncRoot)
        {
            return new SynchronizedDictionaryEnumerator(SyncRoot, _table.GetEnumerator());
        }
    }

    ///<summary>
    ///Removes the element with the specified key from the <see cref="T:System.Collections.IDictionary"></see> object.
    ///</summary>
    ///<param name="key">The key of the element to remove. </param>
    ///<exception cref="T:System.NotSupportedException">The <see cref="T:System.Collections.IDictionary"></see> object is read-only.-or- The <see cref="T:System.Collections.IDictionary"></see> has a fixed size. </exception>
    ///<exception cref="T:System.ArgumentNullException">key is null. </exception><filterpriority>2</filterpriority>
    public void Remove(object key)
    {
        lock (SyncRoot)
        {
            _table.Remove(key);
        }
    }

    ///<summary>
    ///Returns an enumerator that iterates through a collection.
    ///</summary>
    ///<returns>
    ///An <see cref="T:System.Collections.IEnumerator"></see> object that can be used to iterate through the collection.
    ///</returns>
    IEnumerator IEnumerable.GetEnumerator()
    {
        lock (SyncRoot)
        {
            return new SynchronizedEnumerator(SyncRoot, ((IEnumerable) _table).GetEnumerator());
        }
    }

    ///<summary>
    ///Gets or sets the element with the specified key.
    ///</summary>
    ///<returns>
    ///The element with the specified key.
    ///</returns>
    ///<param name="key">The key of the element to get or set. </param>
    ///<exception cref="T:System.NotSupportedException">The property is set and the <see cref="T:System.Collections.IDictionary"></see> object is read-only.-or- The property is set, key does not exist in the collection, and the <see cref="T:System.Collections.IDictionary"></see> has a fixed size. </exception>
    ///<exception cref="T:System.ArgumentNullException">key is null. </exception><filterpriority>2</filterpriority>
    public object this[object key]
    {
        get
        {
            lock (SyncRoot)
            {
                return _table[key];
            }
        }
        set
        {
            lock (SyncRoot)
            {
                _table[key] = value;
            }
        }
    }
}
